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History: Enigma was invented by the German engineer Arthur Scherbius at the end of World War I. The early models were used commercially from the early 1920s, and adopted by military and government services of several countries — significantly by Nazi Germany before and during World War II. The Intelligence Bureau of Poland first broke Germany's military Enigma ciphers in December 1932. After which, they presented their Enigma-decryption techniques and equipment to French and British military. The Enigma machine was an important piece of equipment used by the Germans during the World War II. It was initially designed and used in the civilian world in the 1920s. The German military understood the power of the machine and used it for all sorts of communication – on land, on sea, in air and even within its secret service. By the late 1920s, all commercial Enigma machines have disappeared from the market. Components of the Enigma Machine: The Enigma machine is, in essence, multiple substitution ciphers put together. It has these main components: a keyboard, a light field with small lights for each letter, a set of rotors (the initial machine had 3),The wheel to the right of this space is the fixed entry or plate (Eintrittwalze)and one on its left,the reversing wheel (Umkehrwalze), a reflector, a plug board and a battery. How does it work? When a key is pressed on the key board, a current is sent to the plugboard which is then sent to the rotors. The current first passes the entry plate (E), then to each of the three rotors (N, M, L). At each rotor, a substitution is applied to the letter. The resulting voltage is reflected at the reflector ® and passes through the three rotors where substitutions are applied once more. After going through the three rotors, the current is passed back to the plugboard, and then to the light field. The resulting letter is then lit up on the flight field. Plugboard http://cid-3-cryptography.wikia.com/wiki/Plugboard Strength of the Enigma Machine: The strength of the Enigma lies in the secrecy of the positioning of the rotors, the selection of the initial rotor state and the arrangement of the plugboard wirings. Another strength is that it is hard to crack. First, there are 3 rotors in the Enigma machine. These 3 rotors have a total of 6 ways to be arranged. There are 263 (=17576) ways of setting the initial state of the rotors. Then, there is the wiring in the plugboard. Each letter can be wired to a different letter in the plugboard. If there are 6 connections in the plugboard, this translates to 100,391,791,500 to set the plugboard. Without even considering anything further, the Enigma machine could encrypt a text in about 10^16 different ways! Weakness of the Enigma Machine: There was no letter that could be enciphered to itself. This meant that some possible solutions could quickly be eliminated because of the same letter appearing in the same place in both the ciphertext and the putative piece of plaintext. Why were the Allies able to crack it? 1) The wiring of the rotors was changed seldom, if ever, during the war. The Allies were able to exploit this when they got their hands on Enigma, and thus the rotor wiring. Knowing that information reduces the number of possible code settings to several million, a number easily tackled by the Bombe. (Rotor wiring is what determines which letter is substituted for which when a message goes through the encryption system.) 2) The beginning of a message was often predictable. Usually, the German equivalent of "TO GENERAL SMITH" invariably started a message. Knowing what some of a message reads is usually extremely helpful in cracking a code. CRACKING THE CODE: In 1928 the Poles, who had actively intercepted German signals since the end of the First World War, realized that the Germans had changed to machine encryption because standard attacks, such as frequency counts, were useless. They purchased a commercial version of the Enigma, but it too was useless. The commercial machine used four rotors to cipher the letters and had no plugboard. The German military had made too many changes to the machine for the Poles to make use of the commercial Enigma. What the Germans could have done to strengthen the security of their code: 1) Using more rotors. The Germans had only 3 rotors in most enigmas. With every additional rotor, millions of new permutations must be checked by the cracker. 2) Tightening security of the Enigmas themselves. If the allies had been unable to get even one enigma, it would have been harder to predict how it operated, and find its weaknesses. 3) Having the rotors not move in a speedometer style fashion. By adding more places in the alphabet where the second and third rotor move, it would have become exceedingly difficult for the Bombe to operate. 4)Changing the wiring of the rotors frequently. Although this would have been a major undertaking, the secrecy of rotor wiring supplies the greatest security to the machine. By making them unpredictable, it would have been nearly impossible to crack the Enigma. 5) Keeping tabs on enigma operators to check for protocol breaches. It only takes one foul-up to compromise all encrypted traffic. 6) Add a fixed rotor at the end to serve as a 'reflector' to send back the signals received. YOUTUBE VIDEO: http://m.youtube.com/watch?v=XMK2U3xQQ8A Category:Browse Category:Enigma machine Category:Browse Category:Enigma machine